Sleep Disturbance Is Associated With Higher Plasma A Beta Levels In Cognitively Normal Adults-A Population-Based Cross-Sectional Study

Objective: Growing evidence suggests that sleep disturbance is a risk factor for Alzheimer's disease (AD). Amyloid-beta (A beta) deposition in the brain is a main pathophysiology of AD. Considering that peripheral A beta level is associated with brain A beta deposition, the present study investigated the relationship between sleep disturbance and plasma A beta levels.Methods: This is a population-based cross-sectional study. A total of 1,459 participants from a village in the suburbs of Xi'an, China, were enrolled from January 3, 2017 to March 26, 2017. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and a PSQI score of 10 points as poor sleep quality. Cognitive function was assessed with the Mini-Mental State Examination (MMSE). Fasting venous blood was taken in the morning, and the plasma A beta levels were measured using ELISA. The relationships between plasma A beta levels and sleep quality were analyzed using multiple linear regression.Results: Among the participants, 231 had poor sleep quality (15.83%). The log-transformed A beta(40) level had significant differences among the different sleep groups (F = 3.216, p = 0.040). The log-transformed A beta(40) level was higher in the poor sleep quality group than that in the general sleep quality group [87.17 (73.42, 107.34) vs. 89.69 (74.81, 125.79) pg/ml, p = 0.016]. In bivariate analysis, sleep quality was negatively associated with the log-transformed plasma A beta(40) level (beta = -0.025, p = 0.011).Conclusion: In the community population, poorer sleep quality is associated with a higher plasma A beta(40) level. This indicated that sleep disturbance might also involve in dysfunction of peripheral A beta clearance.